In opposing Obamacare, the tea party took a position that increasing numbers of Americans agree with, now that Obamacare’s potential for disaster is becoming clearer by the day. But in trying to defund Obamacare without the Congressional votes to do so, the tea party made a major tactical mistake.

Polls show that this mistake has already hurt the Republican Party, the only party that has any chance of repealing Obamacare. To have any realistic prospect of repealing Obamacare may require the Republicans to win both the 2014 and 2016 elections.

The tea party’s failed and foredoomed defunding effort predictably got the Republicans blamed for shutting down the government. The fact that the Democrats also went down in the polls means nothing. Politics is a zero-sum game. If it hurts the Republicans more, that helps the Democrats.

Some defend the futile attempt to defund Obamacare on grounds that it is much harder to repeal a law after it has gone into operation. That may often be true — but not always.

Prohibition was repealed — and it was a Constitutional Amendment, not just a piece of legislation. Prohibition could not be repealed by Congress alone, but required state legislatures to vote for repeal as well. Like Obamacare, Prohibition sounded good to a lot of people before it went into effect. Only after they saw what a disaster it was in practice did people change their minds.

We are already seeing people changing their minds about Obamacare, after they experienced the multiple disasters that are just starting to emerge. That includes Congressional Democrats who had voted for it.

If mistakes were always fatal, the human race would have become extinct long ago. So the fact that the tea party made a tactical misjudgment is not the end of the world. Everything depends on whether you learn from your mistake or refuse to admit that it was a mistake, even to yourself — which is often the biggest mistake of all.

Barack Obama is currently giving a free demonstration of how refusing to admit your mistake can cost you public support, and even undermine your support within your own party.

The tea party does not need to repeat the same mistake that Obama has made — especially since their principles are the opposite of his. The tea party is for protecting individual freedom from the ever growing, and ever more intrusive, power of government.

Friend and foe alike see the tea party as not just a bunch of politicians trying to stay in office, but people with a purpose beyond going along to get along. The left’s desperate — and dishonest — efforts to discredit the tea party show that they understand its threat to its expanding government agenda.

The question is whether the tea party itself still has its eye on the ball — the goals it was formed to serve — or is letting itself get preoccupied with its battle against other Republicans.

Heaven knows there are Republicans who deserve criticism. But neither fervor nor ego can justify wholesale challenges to Republican incumbents in next year’s primary elections. The end result of such a self-indulgence is likely to be getting more Democrats elected, making repeal of Obamacare virtually impossible. We can only hope that this is not what the tea party has in mind, not only for its sake, but for the sake of the country.

A haunting example from history was the doctrinaire wing of the abolitionists, who ran their own presidential candidate in the 1860 elections, even though he had no chance of winning, and simply split the anti-slavery vote, so that Abraham Lincoln got just 40 percent of the popular vote when he won in a crowded field.

The doctrinaires were willing to risk a pro-slavery candidate being elected President of the United States at a critical juncture in history, which would have condemned millions of human beings to more decades, or perhaps generations, in slavery.

Whatever your principles, you have to weigh human consequences from whatever you do in the name of those principles.

There are millions of Americans today who are losing their insurance and their doctor — and who may also lose everything financially to identity thieves, if Obamacare is as careless with their private information as early reports indicate. These Americans are infinitely more important than internal battles among Republicans.

Thomas Sowell is a senior fellow at the Hoover Institution, Stanford University, Stanford, CA 94305. His website is www.tsowell.com.